On Wed, Jan 13, 2016 at 12:37:59PM +0530, Aravinda Prasad wrote: > This patch introduces a new KVM capability to control > how KVM behaves on machine check exception (MCE). > Without this capability, KVM redirects machine check > exceptions to guest's 0x200 vector if the address in > error belongs to the guest. With this capability KVM > causes a guest exit with NMI exit reason. > > This is required to avoid problems if a new kernel/KVM > is used with an old QEMU for guests that don't issue > "ibm,nmi-register". As old QEMU does not understand the > NMI exit type, it treats it as a fatal error. However, > the guest could have handled the machine check error > if the exception was delivered to guest's 0x200 interrupt > vector instead of NMI exit in case of old QEMU. > > QEMU part can be found at: > http://lists.nongnu.org/archive/html/qemu-ppc/2015-12/msg00199.html > > Change Log v3: > - Split the patch into 2. First patch introduces the > new capability while the second one enhances KVM to > redirect MCE. > - Fix access width bug > - Rebased to v4.4-rc7 > > Change Log v2: > - Added KVM capability > > Signed-off-by: Aravinda Prasad <[email protected]> > --- > arch/powerpc/include/asm/kvm_host.h | 1 + > arch/powerpc/kernel/asm-offsets.c | 1 + > arch/powerpc/kvm/powerpc.c | 7 +++++++ > include/uapi/linux/kvm.h | 1 + > 4 files changed, 10 insertions(+) > > diff --git a/arch/powerpc/include/asm/kvm_host.h > b/arch/powerpc/include/asm/kvm_host.h > index cfa758c..9ac2b84 100644 > --- a/arch/powerpc/include/asm/kvm_host.h > +++ b/arch/powerpc/include/asm/kvm_host.h > @@ -243,6 +243,7 @@ struct kvm_arch { > int hpt_cma_alloc; > struct dentry *debugfs_dir; > struct dentry *htab_dentry; > + u8 fwnmi_enabled;
Um.. I don't see anything in this patch or 2/2 which actually tests
this flag...
> #endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
> #ifdef CONFIG_KVM_BOOK3S_PR_POSSIBLE
> struct mutex hpt_mutex;
> diff --git a/arch/powerpc/kernel/asm-offsets.c
> b/arch/powerpc/kernel/asm-offsets.c
> index 221d584..6a4e81a 100644
> --- a/arch/powerpc/kernel/asm-offsets.c
> +++ b/arch/powerpc/kernel/asm-offsets.c
> @@ -506,6 +506,7 @@ int main(void)
> DEFINE(KVM_ENABLED_HCALLS, offsetof(struct kvm, arch.enabled_hcalls));
> DEFINE(KVM_LPCR, offsetof(struct kvm, arch.lpcr));
> DEFINE(KVM_VRMA_SLB_V, offsetof(struct kvm, arch.vrma_slb_v));
> + DEFINE(KVM_FWNMI, offsetof(struct kvm, arch.fwnmi_enabled));
> DEFINE(VCPU_DSISR, offsetof(struct kvm_vcpu, arch.shregs.dsisr));
> DEFINE(VCPU_DAR, offsetof(struct kvm_vcpu, arch.shregs.dar));
> DEFINE(VCPU_VPA, offsetof(struct kvm_vcpu, arch.vpa.pinned_addr));
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 6fd2405..a8399b5 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c
> @@ -570,6 +570,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long
> ext)
> r = 1;
> break;
> #endif
> + case KVM_CAP_PPC_FWNMI:
> + r = 1;
> + break;
> default:
> r = 0;
> break;
> @@ -1132,6 +1135,10 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu
> *vcpu,
> break;
> }
> #endif /* CONFIG_KVM_XICS */
> + case KVM_CAP_PPC_FWNMI:
> + r = 0;
> + vcpu->kvm->arch.fwnmi_enabled = true;
> + break;
> default:
> r = -EINVAL;
> break;
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 03f3618..d8a07b5 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -831,6 +831,7 @@ struct kvm_ppc_smmu_info {
> #define KVM_CAP_GUEST_DEBUG_HW_WPS 120
> #define KVM_CAP_SPLIT_IRQCHIP 121
> #define KVM_CAP_IOEVENTFD_ANY_LENGTH 122
> +#define KVM_CAP_PPC_FWNMI 123
>
> #ifdef KVM_CAP_IRQ_ROUTING
>
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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